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3 years ago

Please answer the attached question and chose from the provided options.

Mathematics

1 answer:

Marat540 [252]3 years ago

6 0

Answer:

Option A $-\frac{19}{74}+\frac{71}{74}i$

Step-by-step explanation:

we know that

To divide complex numbers, you must multiply by the conjugate.

we have

$\frac{-8+3i}{5+7i}$

To find the conjugate, change the sign between the two terms in the denominator

$\frac{-8+3i}{5+7i}(\frac{5-7i}{5-7i})=\frac{-40+56i+15i-21i^{2}}{25-49i^{2}} \\\\=\frac{-40+71i-21(-1)}{25-49(-1)} \\\\=\frac{-19+71i}{74}\\\\=-\frac{19}{74}+\frac{71}{74}i$

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32, 28, 21, 31, 18<br><br> Is 18 an outlier or no?

Kryger [21]

Answer:

No because 21 is close to it.

Step-by-step explanation:

To be considered an outlier, it would need to be a farther distance such as the distance from 28 to 21.

Hope this helps!!! PLZ MARK BRAINLIEST!!!

4 0

3 years ago

Read 2 more answers

Freddy’s savings account went from $520 to $321 after he purchased a new bike. What was the percent decrease?

Vinil7 [7]

Step-by-step explanation:

The bike cost $199 to get $199 you do a number line then label 520 then at the end label 321 so then you do -20 then -100 then -50 then -20 then -9. so now you add them up 20+100+50+20+9 which equals =199

so bike cost $199

then 520%×199= 1034.8

or 520%×321=1669.2

so the percentage is 1669.2 or 1034.8 probably 1669.2 but they bot count.

5 0

3 years ago

Making handcrafted pottery usually takes two major steps:wheel throwing and firing. The time of wheel throwing and thetime of fi

levacccp [35]

Answer:

a) $P(R$

And we can find this probability using the normal standard table or excel and we got:

$P(z$

b) $P(R>110)=P(\frac{R-\mu}{\sigma}>\frac{110-\mu}{\sigma})=P(Z>\frac{110-100}{3.606})=P(Z>2.774)$

And we can find this probability using the complement rule and the normal standard table or excel and we got:

$P(z>2.774)=1-P(Z$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Part a

Let X the random variable that represent the time for the step 1 and Y the time for the step 2, we define the random variable R= X+Y for the total time and the distribution for R assuming independence between X and Y is:

$R \sim N(40+60 = 100,\sqrt{2^2 +3^2}= 3.606 s)$

Where $\mu=65.5$ and $\sigma=2.6$

We are interested on this probability

$P(R$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{R-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(R$

And we can find this probability using the normal standard table or excel and we got:

$P(z$

Part b

$P(R>110)=P(\frac{R-\mu}{\sigma}>\frac{110-\mu}{\sigma})=P(Z>\frac{110-100}{3.606})=P(Z>2.774)$

And we can find this probability using the complement rule and the normal standard table or excel and we got:

$P(z>2.774)=1-P(Z$

8 0

3 years ago

Read 2 more answers

Classify the polygons as regular or irregular, and concave or convex. HELP ASAP!! TWO PICTURES!!

mylen [45]

Answer:

First figure is regular and convex.

Second figure is irregular and convex.

Step-by-step explanation:

Here given 2 polygons we have to classify these whether these are convex, concave, regular and irregular.

Regular Polygon is the polygon which have all sides and all angles equal.

Convex Polygon is the polygon in which measure of all interior angles less than 180° and if measure of each of interior angle greater than 180° then it is concave.

In the first figure, all sides are equal therefore and each of interior angle of polygon is less than 180°. Hence, the polygon is regular and convex.

In the second figure, all sides are not equal and each of interior angle of polygon is less than 180°. Hence, the polygon is irregular and convex.

6 0

3 years ago

Parallelogram RSTU is shown.

mixas84 [53]

Answer:

-opposite sides of a parallelogram are congruent.

-definition of a parallelogram

- alternate interior angles are congruent

Step-by-step explanation:

I just did the test

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3 years ago

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